<article id="wikiArticle">
<p></p><p></p>
<p><strong><code>Atomics</code></strong> 对象提供了一组静态方法用来对 <a href="Reference/Global_Objects/SharedArrayBuffer" title="SharedArrayBuffer 对象用来表示一个通用的，固定长度的原始二进制数据缓冲区，类似于 ArrayBuffer 对象，它们都可以用来在共享内存（shared memory）上创建视图。与 ArrayBuffer 不同的是，SharedArrayBuffer 不能被分离。"><code>SharedArrayBuffer</code></a> 对象进行原子操作。</p>
<p>这些原子操作属于 <code>Atomics</code> 模块。与一般的全局对象不同，<code>Atomics</code> 不是构造函数，因此不能使用 <a href="https://developer.mozilla.orgReference/Operators/new">new</a> 操作符调用，也不能将其当作函数直接调用。<code>Atomics</code> 的所有属性和方法都是静态的（与 <a href="Reference/Global_Objects/Math" title="Math 是一个内置对象， 它具有数学常数和函数的属性和方法。不是一个函数对象。"><code>Math</code></a>  对象一样）。</p>
<h2 id="属性">属性</h2>
<dl>
<dt><code>Atomics[Symbol.toStringTag]</code></dt>
<dd>该属性的值为“Atomics”。</dd>
</dl>
<h2 id="方法">方法</h2>
<h3 id="原子操作">原子操作</h3>
<p>多个共享内存的线程能够同时读写同一位置上的数据。原子操作会确保正在读或写的数据的值是符合预期的，即下一个原子操作一定会在上一个原子操作结束后才会开始，其操作过程不会中断。</p>
<dl>
<dt><span style="display: none;"> </span></dt>
<dt><a href="Reference/Global_Objects/Atomics/add" title="Atomics.add() 静态方法会将给定的值加到数组里的某个特定位置上，并返回该位置的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.add()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相加，并返回相加前该元素的值。</dd>
<dt><strong><a href="Reference/Global_Objects/Atomics/and" title="Atomics.and() 静态方法会将给定的值与数组上的值进行按位与操作，并将结果赋值给数组，然后返回数组该位置上的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.and()</code></a></strong></dt>
<dd>将指定位置上的数组元素与给定的值相与，并返回与操作前该元素的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/compareExchange" title="Atomics.compareExchange() 静态方法会在数组的值与期望值相等的时候，将给定的替换值替换掉数组上的值，然后返回旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.compareExchange()</code></a></dt>
<dd>如果数组中指定的元素与给定的值相等，则将其更新为新的值，并返回该元素原先的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/exchange" title="Atomics.exchange() 静态方法会用给定的值替换掉数组上的值，然后返回数组的旧值。此原子操作保证在写上修改的值之前不会发生其他写操作。"><code>Atomics.exchange()</code></a></dt>
<dd>将数组中指定的元素更新为给定的值，并返回该元素更新前的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/load" title="静态方法 Atomics.load() 返回一个数组当中给定位置的值。"><code>Atomics.load()</code></a></dt>
<dd>返回数组中指定元素的值。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/or" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.or()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相或，并返回或操作前该元素的值。</dd>
<dt><a href="Reference/Global_Objects/Atomics/store" title="静态的Atomics.store（）方法将给定的值存储在数组中的指定位置，并返回该值。."><code>Atomics.store()</code></a></dt>
<dd>将数组中指定的元素设置为给定的值，并返回<strong>该值</strong>。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/sub" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.sub()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相减，并返回相减前该元素的值。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/xor" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.xor()</code></a></dt>
<dd>将指定位置上的数组元素与给定的值相异或，并返回异或操作前该元素的值。</dd>
</dl>
<h3 id="等待和唤醒">等待和唤醒</h3>
<p><code>wait()</code> 和 <code>wake()</code> 方法采用的是 Linux 上的 futexes 模型（fast user-space mutex，快速用户空间互斥量），可以让进程一直等待直到某个特定的条件为真，主要用于实现阻塞。</p>
<dl>
<dt><a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a></dt>
<dd>检测数组中某个指定位置上的值是否仍然是给定值，是则保持挂起直到被唤醒或超时。返回值为 "<code>ok</code>"、"<code>not-equal</code>" 或 "<code>time-out</code>"。调用时，如果当前线程不允许阻塞，则会抛出异常（大多数浏览器都不允许在主线程中调用 <code>wait()</code>）。</dd>
<dt><a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a></dt>
<dd>唤醒等待队列中正在数组指定位置的元素上等待的线程。返回值为成功唤醒的线程数量。</dd>
<dt><a href="Reference/Global_Objects/Atomics/isLockFree" title="静态方法 Atomics.isLockFree() 用于校验是否能够使用原子操作的TypedArray的标准字节长度之一. 若该字节长度为可处理的TypedArray标准字节长度之一则返回  true.  TypedArray的标准字节长度参见 BYTES_PER_ELEMENT"><code>Atomics.isLockFree(size)</code></a></dt>
<dd>可以用来检测当前系统是否支持硬件级的原子操作。对于指定大小的数组，如果当前系统支持硬件级的原子操作，则返回 <code>true</code>；否则就意味着对于该数组，<code>Atomics</code> 对象中的各原子操作都只能用锁来实现。此函数面向的是技术专家。</dd>
</dl>
<h2 id="规范">规范</h2>
<table class="standard-table">
<tbody>
<tr>
<th scope="col">规范</th>
<th scope="col">状态</th>
<th scope="col">说明</th>
</tr>
<tr>
<td><a class="external" href="https://tc39.github.io/ecma262/#sec-atomics-object" hreflang="en" lang="en" rel="noopener">ECMAScript Latest Draft (ECMA-262)<br/><small lang="zh-CN">Atomics</small></a></td>
<td><span class="spec-Draft">Draft</span></td>
<td>ES2017 中的初始定义</td>
</tr>
<tr>
<td><a class="external" href="https://www.ecma-international.org/ecma-262/8.0/#sec-atomics-object" hreflang="en" lang="en" rel="noopener">ECMAScript 2017 (ECMA-262)<br/><small lang="zh-CN">Atomics</small></a></td>
<td><span class="spec-Standard">Standard</span></td>
<td> </td>
</tr>
</tbody>
</table>
<h2 id="浏览器兼容性">浏览器兼容性</h2>
<div class="hidden">The compatibility table on this page is generated from structured data. If you'd like to contribute to the data, please check out <a class="external" href="https://github.com/mdn/browser-compat-data" rel="noopener">https://github.com/mdn/browser-compat-data</a> and send us a pull request.</div>
<p></p><div class="bc-data"><a class="bc-github-link external" href="https://github.com/mdn/browser-compat-data" rel="noopener">Update compatibility data on GitHub</a><table class="bc-table bc-table-js"><thead><tr class="bc-platforms"><td></td><th class="bc-platform-desktop" colspan="6"><span>Desktop</span></th><th class="bc-platform-mobile" colspan="7"><span>Mobile</span></th><th class="bc-platform-server" colspan="1"><span>Server</span></th></tr><tr class="bc-browsers"><td></td><th class="bc-browser-chrome"><span class="bc-head-txt-label bc-head-icon-chrome">Chrome</span></th><th class="bc-browser-edge"><span class="bc-head-txt-label bc-head-icon-edge">Edge</span></th><th class="bc-browser-firefox"><span class="bc-head-txt-label bc-head-icon-firefox">Firefox</span></th><th class="bc-browser-ie"><span class="bc-head-txt-label bc-head-icon-ie">Internet Explorer</span></th><th class="bc-browser-opera"><span class="bc-head-txt-label bc-head-icon-opera">Opera</span></th><th class="bc-browser-safari"><span class="bc-head-txt-label bc-head-icon-safari">Safari</span></th><th class="bc-browser-webview_android"><span class="bc-head-txt-label bc-head-icon-webview_android">Android webview</span></th><th class="bc-browser-chrome_android"><span class="bc-head-txt-label bc-head-icon-chrome_android">Chrome for Android</span></th><th class="bc-browser-edge_mobile"><span class="bc-head-txt-label bc-head-icon-edge_mobile">Edge Mobile</span></th><th class="bc-browser-firefox_android"><span class="bc-head-txt-label bc-head-icon-firefox_android">Firefox for Android</span></th><th class="bc-browser-opera_android"><span class="bc-head-txt-label bc-head-icon-opera_android">Opera for Android</span></th><th class="bc-browser-safari_ios"><span class="bc-head-txt-label bc-head-icon-safari_ios">Safari on iOS</span></th><th class="bc-browser-samsunginternet_android"><span class="bc-head-txt-label bc-head-icon-samsunginternet_android">Samsung Internet</span></th><th class="bc-browser-nodejs"><span class="bc-head-txt-label bc-head-icon-nodejs">Node.js</span></th></tr></thead><tbody><tr><th scope="row"><code>Atomics</code></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect1"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect2"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect3"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect4"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect5"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect6"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/add"><code>add</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect7"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect8"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect9"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect10"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect11"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect12"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/and"><code>and</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect13"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect14"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect15"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect16"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect17"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect18"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/compareExchange"><code>compareExchange</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect19"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect20"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect21"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect22"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect23"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect24"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/exchange"><code>exchange</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect25"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect26"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect27"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect28"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect29"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect30"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/isLockFree"><code>isLockFree</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect31"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect32"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect33"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect34"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect35"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect36"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/load"><code>load</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect37"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect38"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect39"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect40"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect41"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect42"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/notify" rel="nofollow"><code>notify</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect43"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect44"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect45"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 63: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The <code>count</code> parameter defaults to <code>0</code> instead of the later-specified <code>+Infinity</code>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari bc-has-history"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect46"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect47"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect48"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect49"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 63: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The <code>count</code> parameter defaults to <code>0</code> instead of the later-specified <code>+Infinity</code>.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWake</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs bc-has-history"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div><section class="bc-history" id="sect50"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0<div class="bc-icons"><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> </div></dt><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;wake&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>wake</code></dd></dl></section></td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/or" rel="nofollow"><code>or</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect51"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect52"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect53"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect54"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect55"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect56"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a href="Reference/Global_Objects/Atomics/store"><code>store</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect57"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect58"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect59"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect60"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect61"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect62"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/sub" rel="nofollow"><code>sub</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect63"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect64"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect65"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect66"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect67"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled SharedArrayBuffer on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect68"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow"><code>wait</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect69"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect70"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect71"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The method returns values <code>Atomics.OK</code>, <code>Atomics.TIMEDOUT</code>, and <code>Atomics.NOTEQUAL</code>, instead of the later-specified strings.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWait</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect72"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect73"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect74"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>48 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 48 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 48<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> The method returns values <code>Atomics.OK</code>, <code>Atomics.TIMEDOUT</code>, and <code>Atomics.NOTEQUAL</code>, instead of the later-specified strings.</dd><dd><abbr class="only-icon" title="Uses the non-standard name: &lt;code&gt;futexWait&lt;/code&gt;"><span>Alternate Name</span><i class="ic-altname"></i></abbr> Uses the non-standard name: <code>futexWait</code></dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 48 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr><tr><th scope="row"><a class="new" href="Reference/Global_Objects/Atomics/xor" rel="nofollow"><code>xor</code></a></th><td class="bc-supports-yes bc-browser-chrome bc-has-history"><span class="bc-browser-name">Chrome</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div><section class="bc-history" id="sect75"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              68<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This was a temporary removal while mitigations were put in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-edge bc-has-history"><span class="bc-browser-name">Edge</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect76"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>16 — 17<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was removed to mitigate <a class="external" href="https://blogs.windows.com/msedgedev/2018/01/03/speculative-execution-mitigations-microsoft-edge-internet-explorer" rel="noopener">speculative execution side-channel attacks (Windows blog)</a>.</dd></dl></section></td><td class="bc-supports-yes bc-browser-firefox bc-has-history"><span class="bc-browser-name">Firefox</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect77"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-ie"><span class="bc-browser-name">IE</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-opera"><span class="bc-browser-name">Opera</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari"><span class="bc-browser-name">Safari</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>10.1 — ?</td><td class="bc-supports-no bc-browser-webview_android bc-has-history"><span class="bc-browser-name">WebView Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect78"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-no bc-browser-chrome_android bc-has-history"><span class="bc-browser-name">Chrome Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div><section class="bc-history" id="sect79"><dl><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>60 — 63<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Chrome disabled <code>SharedArrayBuffer</code> on January 5, 2018 to help reduce the efficacy of <a class="external" href="https://www.chromium.org/Home/chromium-security/ssca" rel="noopener">speculative side-channel attacks</a>. This is intended as a temporary measure until other mitigations are in place.</dd></dl></section></td><td class="bc-supports-unknown bc-browser-edge_mobile"><span class="bc-browser-name">Edge Mobile</span><abbr title="Compatibility unknown; please update this.">
                ?
              </abbr></td><td class="bc-supports-yes bc-browser-firefox_android bc-has-history"><span class="bc-browser-name">Firefox Android</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div><section class="bc-history" id="sect80"><dl><dt class="bc-supports-yes bc-supports"><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              57<div class="bc-icons"><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> <abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="See implementation notes"><span>Notes</span><i class="ic-footnote"></i></abbr> Support was disabled by default to mitigate <a class="external" href="https://blog.mozilla.org/security/2018/01/03/mitigations-landing-new-class-timing-attack/" rel="noopener">speculative execution side-channel attacks (Mozilla Security Blog)</a>.</dd><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 57: this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>55 — 57<div class="bc-icons"></div></dt><dd></dd><dt class="bc-supports-no bc-supports"><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>46 — 55<div class="bc-icons"><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> </div></dt><dd><abbr class="only-icon" title="User must explicitly enable this feature."><span>Disabled</span><i class="ic-disabled"></i></abbr> From version 46 until version 55 (exclusive): this feature is behind the <code>javascript.options.shared_memory</code> preference (needs to be set to <code>true</code>). To change preferences in Firefox, visit about:config.</dd></dl></section></td><td class="bc-supports-no bc-browser-opera_android"><span class="bc-browser-name">Opera Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-safari_ios"><span class="bc-browser-name">Safari iOS</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-no bc-browser-samsunginternet_android"><span class="bc-browser-name">Samsung Internet Android</span><abbr class="bc-level-no only-icon" title="No support">
<span>No support</span>
</abbr>
              No</td><td class="bc-supports-yes bc-browser-nodejs"><span class="bc-browser-name">nodejs</span><abbr class="bc-level-yes only-icon" title="Full support">
<span>Full support</span>
</abbr>
              8.10.0</td></tr></tbody></table><section class="bc-legend" id="sect81"><h3 class="offscreen" id="Legend">Legend</h3><dl><dt><span class="bc-supports-yes bc-supports">
<abbr class="bc-level bc-level-yes only-icon" title="Full support">
<span>Full support</span>
                  
                </abbr></span></dt><dd>Full support</dd><dt><span class="bc-supports-no bc-supports">
<abbr class="bc-level bc-level-no only-icon" title="No support">
<span>No support</span>
                  
                </abbr></span></dt><dd>No support</dd><dt><span class="bc-supports-unknown bc-supports">
<abbr class="bc-level bc-level-unknown only-icon" title="Compatibility unknown">
<span>Compatibility unknown</span>
                  
                </abbr></span></dt><dd>Compatibility unknown</dd><dt><abbr class="only-icon" title="See implementation notes."><span>See implementation notes.</span><i class="ic-footnote"></i></abbr></dt><dd>See implementation notes.</dd><dt><abbr class="only-icon" title="User must explicitly enable this feature."><span>User must explicitly enable this feature.</span><i class="ic-disabled"></i></abbr></dt><dd>User must explicitly enable this feature.</dd><dt><abbr class="only-icon" title="Uses a non-standard name."><span>Uses a non-standard name.</span><i class="ic-altname"></i></abbr></dt><dd>Uses a non-standard name.</dd></dl></section></div><p></p>
<h2 id="兼容性提示">兼容性提示</h2>
<p>直到 Firefox 48，最新的 API 名称和语意都还没有实现。FirFox 46 到 FireFox 48 之间主要有以下变化:</p>
<ul>
<li>移除了方法 <code>Atomics.futexWakeOrRequeue()</code> 和 <code>Atomics.fence()</code> （bug(1259544)、bug(1225028)）。</li>
<li> <a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a> 和 <a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a> 方法名称已改为 <code>Atomics.futexWait()</code> 和 <code>Atomics.futexWake()</code>（<a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1260910" rel="noopener" title="FIXED: Rename Atomics.{futexWait,futexWake} as Atomics.{wait,wake}">bug 1260910</a>）。注意：之前的名称在 49 版本之后已被移除（<a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1262062" rel="noopener" title="FIXED: Remove futexWait and futexWake aliases after FF48 branches">bug 1262062</a>）</li>
<li>移除了属性 <code>Atomics.OK</code>、 <code>Atomics.TIMEDOUT</code>、 <code>Atomics.NOTEQUAL</code>。<a class="new" href="Reference/Global_Objects/Atomics/wait" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wait()</code></a> 方法现在返回字符串 "ok"、"timed-out" 和 "not-equal" （<a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1260835" rel="noopener" title="FIXED: Remove Atomics.{OK,NOTEQUAL,TIMEDOUT}, return strings from Atomics.futexWait instead">bug 1260835</a>）。</li>
<li>
<p><a class="new" href="Reference/Global_Objects/Atomics/wake" rel="nofollow" title="此页面仍未被本地化, 期待您的翻译!"><code>Atomics.wake()</code></a> 方法的 <code>count</code> 参数的默认值从 <code>0</code> 变为 <code>+Infinity</code>（<a class="external" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1253350" rel="noopener" title='FIXED: Shared memory spec change: futexWake / futexWakeOrRequeue "count" argument'>bug 1253350</a>）。</p>
</li>
</ul>
<h2 id="相关链接">相关链接</h2>
<ul>
<li><a href="Reference/Global_Objects/ArrayBuffer" title="The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone https://github.com/mdn/interactive-examples and send us a pull request."><code>ArrayBuffer</code></a></li>
<li><a href="Typed_arrays">JavaScript typed arrays</a></li>
<li><a href="/zh-CN/docs/Web/API/Web_Workers_API">Web Workers</a></li>
<li><a class="external" href="https://github.com/lars-t-hansen/parlib-simple" rel="noopener">parlib-simple </a>– a simple library providing synchronization and work distribution abstractions.</li>
<li><a class="external" href="https://github.com/tc39/ecmascript_sharedmem/blob/master/TUTORIAL.md" rel="noopener">Shared Memory – a brief tutorial</a></li>
<li><a class="external" href="https://hacks.mozilla.org/2016/05/a-taste-of-javascripts-new-parallel-primitives/" rel="noopener">A Taste of JavaScript’s New Parallel Primitives – Mozilla Hacks</a></li>
</ul>
</article>